The pro-environment League of Conservation Voters said Monday that it plans to knock on 219,000 doors between now and the April 30 primary, handing out pro-Markey literature. The group plans to be active in nearly 30 communities, none of which are in Western Massachusetts. (League of Conservation Voters spokesman Jeff Gohringer said the campaign could grow, but those are the communities where the League ran a successful field campaign in 2012.) The group endorsed Markey in January and has since raised about $100,000 for his campaign.

“This field campaign will make sure primary voters know that Ed Markey is the only candidate in this race that has written some of the most historic environmental legislation ever considered by Congress,” said Navin Nayak, the League’s senior vice president of campaigns, in a statement. “When voters know about Ed Markey’s record of being a champion in the fight to address the climate crisis and stand up to Big Oil, they’ll send him to the United States Senate to fight for them.”

The group was similarly active in the November U.S. Senate race between Republican Scott Brown and Democrat Elizabeth Warren, spending more than $870,000 on a field campaign supporting Warren. (Brown and Warren also signed a “People’s Pledge” barring outside advertising.)

Though both Lynch and Markey have nearly identical voting records on environmental issues, according to the League’s own scorecard, the group has praised Markey, the ranking member of the House Natural Resources Committee, for his leadership. In particularl, the group points to Markey’s work helping write the American Clean Energy and Security Act, a bill that would have instituted a cap and trade system for greenhouse gas emissions and put in place other policies aimed at curbing climate change. The bill passed the U.S. House in 2009 but died in the U.S. Senate.

Lynch spokesman Conor Yunits said, “I think it’s too bad this group is working so hard against Congressman Lynch given that he votes with them 94 percent of the time over course of his career, the same as Ed Markey.”

Gohringer declined to criticize Lynch’s record, but said, “It’s not very often we get to help elect someone who has literally written some of the most important environmental legislation that Congress ever considered.”

Asked about the League’s involvement, in light of Markey’s attempts to keep outside money out of the race, Markey spokeswoman Giselle Barry said, "Unlike the Republicans in this Senate race who flatly refuse to follow the lead of Scott Brown and reject the influence of Karl Rove, the Koch brothers and outside special interest groups in our elections, Rep. Markey is fully committed to the People’s Pledge and to passing a constitutional amendment that would repeal the court’s misguided Citizens United ruling."